1. Field of the Invention
The present invention relates to a garbage treatment apparatus, and more particularly to a garbage treatment apparatus of the type in which porous inorganic balls containing microorganism are used to decompose garbage into sludge and gases.
2. Description of the Prior Art
In recent years, there has been proposed a treatment method of garbage in which an amount of sintered porous inorganic balls (in the form of porous ceramic balls of about 5-12 mm in diameter) containing microorganism effective for decomposition of garbage is stored in a treatment container and mixed with garbage put into the treatment container so that the garbage is fermented by the microorganism and decomposed into sludge and gases. In such a treatment method, the garbage is crushed by the inorganic balls into fine particles and decomposed in a short time by ferment caused by the microorganism.
As a method of mixing the garbage with the porous inorganic balls, there have been proposed a method of agitating the garbage and inorganic balls by means of agitating blades rotated in a vertical direction within a treatment container and a method of mixing the inorganic balls and garbage by vibration in a treatment container. In the former method, the garbage can be crushed by the agitating blades into fine particles to enhance mixing efficiency with the inorganic balls. However, a large driving force is required to rotate the agitating blades against a resistance caused by the garbage, and there will occur unpleasant noises during rotation of the agitating blades. In the former method, it is also required to rotate the agitating blades at a position near the inner peripheral wall of the container for sufficient agitation of the inorganic balls. In this instance, the inorganic balls are crushed by the agitating blades if brought into a space between the inner peripheral wall of the container and distal ends of the agitating blades. If the inorganic balls were crushed into fine particles, the property of the microorganism would be deteriorated. For this reason, it is required to frequently replenish fresh inorganic balls in the treatment container.
In the latter method described above, it takes a long time for treatment of the garbage since the vibration of the container does not effect to sufficiently mix the garbage with the inorganic balls and to crush the garbage into fine particles in addition, if the vibration of the container causes the garbage and inorganic balls to lump at the bottom of the container, it is required to remove a lump of garbage and inorganic balls from the container.
Additionally, in both the treatment methods, residual sludge of the garbage is adhered to the inorganic balls and remains in the container after treatment of the garbage. If left in the container for a long time, the residual sludge of garbage will harden on the inorganic balls. This deteriorates the decomposition property of the inorganic balls and occurs bad smell. To avoid such a problem, it is required to frequently wash the inorganic balls and the interior of the container in a clean condition.
It is, therefore, a primary object of the present invention to provide a garbage treatment apparatus wherein the garbage and inorganic balls are uniformly mixed without causing crush of the inorganic balls during treatment of the garbage, and wherein residual sludge adhered to the inorganic balls can be removed by washing in a simple manner after treatment of the garbage.
According to the present invention, the object is attained by providing a garbage treatment apparatus of the type which includes a cylindrical container formed to store an amount of porous inorganic balls containing microorganism effective for decomposition of garbage and to store an amount of garbage to be treated, a rotation shaft vertically mounted for rotary movement in a central portion of the container; a driving mechanism mounted on the container for driving the rotation shaft a screw propeller assembly mounted to a lower portion of the rotation shaft for rotation therewith to feed downward the inorganic balls and garbage stored in the container a flow adjustment plate in the form of a truncated conical plate mounted within a bottom portion of the container concentrically with the rotation shaft and placed in an upwardly expanded condition, and a rotary disk horizontally mounted to a lower end of the rotation shaft for rotation therewith and placed under the propeller assembly, the rotary disk being coupled with the flow adjustment plate to close a lower end opening of the adjustment plate and being rotatable relative to the flow adjustment plate, wherein the inorganic balls and garbage stored in the container are agitated by the propeller assembly during rotation of the rotation shaft and moved downward at the central portion of the container to flow upward along the flow adjustment plate and the inner peripheral wall of the container.
According to an aspect of the present invention, an annular space is formed between an upper end periphery of the flow adjustment plate and the inner periphery wall of the container to discharge therethrough, residual sludge of the garbage decomposed by microorganism in the inorganic balls, and a discharge hole is formed in a bottom plate of the container to discharge therethrough the residual sludge from the annular space.
In a practical embodiment of the present invention, it is preferable that a shower nozzle is provided within an upper portion of the container to be supplied with fresh water from an external water source for washing out residual sludge adhered to the inorganic balls and the interior of the container during rotation of the rotation shaft. It is also preferable that a second flow adjustment plate in the form of a truncated conical plate is mounted to the inner peripheral wall of the container to cover the annular space between the upper end periphery of the first-named flow adjustment plate and the inner peripheral wall of the container, wherein the second flow adjustment plate is spaced at its lower end from the upper end periphery of the first-named flow adjustment plate to discharge the residual sludge of garbage.